Coronary Drug Project - CDP


Long-term lipid lowering for secondary mortality prevention after MI.


The long-term lowering of serum lipids in individuals with coronary heart disease (CHD), through the use of cholesterol-lowering drugs, would have a beneficial effect on morbidity and mortality.

Study Design

Study Design:

Patients Screened: Not given
Patients Enrolled: 8,341
NYHA Class: I (46%); II (54%)
Mean Follow Up: 6.2 years (original project); 8.8 years after study termination
Mean Patient Age: 52.4
Female: 0

Patient Populations:

>30 and < 64 years of age
ECG-documented MI at least 3 months before entry of type not listed in exclusions
NYHA Class I or Class II
Willing and able to take CDP study medication, as determined during a 2-month control period
Willing to follow the study protocol for > 5 years after attending an orientation session at which the study drugs and their characteristic side effects were discussed


Previous MI probably caused by coronary artery embolism, aortic dissection, or prolonged arrhythmias.
Previous surgery for coronary artery disease.
Life-limiting disease other than CHD (e.g., malignancy, pulmonary insufficiency, chronic hepatic disease).
Disease which might affect long-term follow-up (e.g., cerebrovascular disease with mental aberration, psychosis, alcoholism).
Conditions which would contraindicate the use of any of the drugs used in the study (e.g., active gastric or duodenal ulceration, hypothyroidism requiring thyroid replacement therapy).
Anticoagulant therapy, lipid-influencing drugs, or insulin at time of entry

Primary Endpoints:

Overall mortality

Secondary Endpoints:

CHD mortality
Sudden death
Nonfatal MI
Nonfatal acute coronary insufficiency (ACI)
Other nonfatal cardiovascular events such as angina pectoris, stroke, arrhythmias, congestive heart failure (CHF), pulmonary embolism

Drug/Procedures Used:

Equine estrogens 2.5 mg/day
Equine estrogens 5 mg/day
Clofibrate 1.8 g/day
Dextrothyroxine 6.0 mg/day
Nicotinic acid (niacin) 3.0 g/day

Concomitant Medications:


Principal Findings:

During the original 6-year study period, mortality rates were:
Total mortality, 27.9%.
Low-dose estrogen group, 28.8%; high-dose estrogen group 28.9% (discontinued because of excess cancer mortality as compared with placebo).
Clofibrate group, 28.2%.
Dextrothyroxine group, 27% (discontinued because of excess cancer mortality as compared with placebo).
Niacin group, 26.1%.
Placebo group, 28%.

At 15-year follow-up, only the niacin group's mortality differed significantly from that of the placebo group (11%, p= 0.0004).

The niacin group showed decreased mean serum cholesterol from baseline to year 1 by 10.1%. Also within the niacin group, patients with the largest decrease in serum cholesterol at 1 year experienced a lower subsequent mortality than those with an increase in serum cholesterol. There was no significant correlation between change in serum triglyceride and mortality in the niacin group.

During the 15-year follow-up period, mortality rates were:
Low-dose estrogen group, 59.7%; high-dose estrogen group, 58.3%.
Clofibrate group, 57.8%.
Dextrothyroxine group, 57.0%.
Niacin group, 52.0%.
Placebo group, 58.2%.


Follow-up data on patients who participated in the CDP suggest that niacin administered after recovery from MI may confer a long-term survival benefit, averaging 1.6 additional years of life. There is no information on whether longer-term niacin usage might be helpful or harmful, whether the drug is effective in women after MI, or whether the drug has any value in the primary prevention of CHD.


1. Circulation 1973;17-18 (suppl I) I-1-I-49. Trial design
2. J AM Coll Cardiol 1986;8:1245-55. 15-year mortality results

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Prevention, Hypertriglyceridemia, Lipid Metabolism, Nonstatins, Statins

Keywords: Neoplasms, Dextrothyroxine, Cytidine Diphosphate, Coronary Disease, Electrocardiography, Cholesterol, Clofibrate, Secondary Prevention, Estrogens, Hypolipidemic Agents, Niacin, Triglycerides

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